diff --git a/client/src/app/site/assignments/modules/assignment-poll/components/assignment-poll-vote/assignment-poll-vote.component.html b/client/src/app/site/assignments/modules/assignment-poll/components/assignment-poll-vote/assignment-poll-vote.component.html
index 0555da609..931427966 100644
--- a/client/src/app/site/assignments/modules/assignment-poll/components/assignment-poll-vote/assignment-poll-vote.component.html
+++ b/client/src/app/site/assignments/modules/assignment-poll/components/assignment-poll-vote/assignment-poll-vote.component.html
@@ -149,7 +149,7 @@
 
 <ng-template #sendNow let-delegation="delegation">
     <div class="centered-button-wrapper">
-        <button mat-flat-button color="accent" (click)="submitVote(delegation)">
+        <button mat-flat-button color="accent" (click)="submitVote(delegation)" [disabled]="getVotesCount(delegation) == 0">
             <mat-icon> how_to_vote </mat-icon>
             <span>
                 {{ 'Submit vote now' | translate }}
diff --git a/server/openslides/assignments/views.py b/server/openslides/assignments/views.py
index 9f00f055a..73790b9ad 100644
--- a/server/openslides/assignments/views.py
+++ b/server/openslides/assignments/views.py
@@ -407,6 +407,8 @@ class AssignmentPollViewSet(BasePollViewSet):
                 )
 
         else:
+            if isinstance(data, dict) and len(data) == 0:
+                raise ValidationError({"details": "Empty ballots are not allowed"})
             available_options = poll.get_options()
             if poll.pollmethod == AssignmentPoll.POLLMETHOD_VOTES:
                 if isinstance(data, dict):
@@ -419,9 +421,7 @@ class AssignmentPollViewSet(BasePollViewSet):
                                 {"detail": f"Option {option_id} does not exist."}
                             )
                         if not is_int(amount):
-                            raise ValidationError(
-                                {"detail": "Each amounts must be int"}
-                            )
+                            raise ValidationError({"detail": "Each amount must be int"})
                         amount = int(amount)
                         if amount < 0:
                             raise ValidationError(
diff --git a/server/tests/integration/assignments/test_polls.py b/server/tests/integration/assignments/test_polls.py
index 090f4ff2f..14519daff 100644
--- a/server/tests/integration/assignments/test_polls.py
+++ b/server/tests/integration/assignments/test_polls.py
@@ -1174,10 +1174,10 @@ class VoteAssignmentPollNamedYNA(VoteAssignmentPollBaseTestClass):
         response = self.client.post(
             reverse("assignmentpoll-vote", args=[self.poll.pk]), {"data": {}}
         )
-        self.assertHttpStatusVerbose(
-            response, status.HTTP_200_OK
-        )  # new "feature" because of partial requests: empty requests work!
+        self.assertHttpStatusVerbose(response, status.HTTP_400_BAD_REQUEST)
         self.assertFalse(AssignmentVote.objects.exists())
+        poll = AssignmentPoll.objects.get()
+        self.assertNotIn(self.admin.id, poll.voted.all())
 
     def test_wrong_data_format(self):
         self.start_poll()
@@ -1459,8 +1459,10 @@ class VoteAssignmentPollNamedVotes(VoteAssignmentPollBaseTestClass):
         response = self.client.post(
             reverse("assignmentpoll-vote", args=[self.poll.pk]), {"data": {}}
         )
-        self.assertHttpStatusVerbose(response, status.HTTP_200_OK)
+        self.assertHttpStatusVerbose(response, status.HTTP_400_BAD_REQUEST)
         self.assertFalse(AssignmentVote.objects.exists())
+        poll = AssignmentPoll.objects.get()
+        self.assertNotIn(self.admin.id, poll.voted.all())
 
     def test_wrong_data_format(self):
         self.start_poll()
@@ -1650,8 +1652,10 @@ class VoteAssignmentPollPseudoanonymousYNA(VoteAssignmentPollBaseTestClass):
         response = self.client.post(
             reverse("assignmentpoll-vote", args=[self.poll.pk]), {"data": {}}
         )
-        self.assertHttpStatusVerbose(response, status.HTTP_200_OK)
+        self.assertHttpStatusVerbose(response, status.HTTP_400_BAD_REQUEST)
         self.assertFalse(AssignmentVote.objects.exists())
+        poll = AssignmentPoll.objects.get()
+        self.assertNotIn(self.admin.id, poll.voted.all())
 
     def test_wrong_data_format(self):
         self.start_poll()
@@ -1883,8 +1887,10 @@ class VoteAssignmentPollPseudoanonymousVotes(VoteAssignmentPollBaseTestClass):
         response = self.client.post(
             reverse("assignmentpoll-vote", args=[self.poll.pk]), {"data": {}}
         )
-        self.assertHttpStatusVerbose(response, status.HTTP_200_OK)
+        self.assertHttpStatusVerbose(response, status.HTTP_400_BAD_REQUEST)
         self.assertFalse(AssignmentVote.objects.exists())
+        poll = AssignmentPoll.objects.get()
+        self.assertNotIn(self.admin.id, poll.voted.all())
 
     def test_wrong_data_format(self):
         self.start_poll()